Leader Ed Miliband gave a string of stirring speeches to delegates in ­Manchester, saying the time was ripe for them to march back into power.

More than 11,000 delegates met last week for the five-day conference to discuss key ­decisions to help Labour win the next ­election – including drug policies.

But our team found irrefutable evidence of misuse of the Class A substance at the city’s four-star Midland Hotel, which was taken over by the party during the event.

Last Wednesday our reporters, armed with simple-to-use but accurate cocaine-testing swabs – like those used by the police – targeted the ­Midland. We also checked the nearby Radisson ­Edwardian Hotel and a Starbucks coffee shop near the conference hall.

In all three venues our swabs tested ­positive for cocaine.

The Midland was closed to anyone ­without Labour party accreditation.

But our reporter was escorted in by the concierge after requesting details about booking a function room.

The foyer was packed with delegates and our man slipped away to use the male toilets.

Two of the three cubicles were in use so our investigator locked himself in the free stall and swabbed the top of the toilet lid.

It immediately turned a tell-tale blue ­colour to indicate cocaine had been taken in the cubicle.

Next, our team walked the 50 yards to the Radisson, which was busy with delegates taking coffee in reception and drinking in the bar.

In the toilets there, the third stall we tested proved positive after the swab was wiped across the loo.

At the Starbucks across the road from both hotels, ­virtually every seat was ­taken by delegates wearing accreditation.

We used another fresh swab in the unisex toilet, which immediately turned blue.

Our investigation shows ­cocaine is now a major part of politics.

Last year Mr Miliband was forced to bat away questions about whether a senior spin doctor had a cocaine problem.

Tory peer Lord Ashcroft had accused Labour’s ­communications guru Tom Baldwin of having been a heavy abuser of the drug in the past.

Asked about the allegation, Mr ­Miliband said: “I’m not going into what people did in their private lives.

“If he has evidence, he should come ­forward with it.”

The estimated number of cocaine users in Britain has soared from 180,000 in 1996 to well over one million now – with almost 400,000 coke users aged under 25.